Lab Papers (GRASP)

Document Type

Journal Article

Subject Area


Date of this Version


Publication Source

IEEE Robotics and Automation Letters



Bib Tex

@ARTICLE{9477019, author={Feshbach, Daniel A. and Sung, Cynthia}, journal={IEEE Robotics and Automation Letters}, title={Reconfiguring Non-Convex Holes in Pivoting Modular Cube Robots}, year={2021}, volume={}, number={}, pages={1-1}, doi={10.1109/LRA.2021.3095030}}


We present an algorithm for self-reconfiguration of admissible 3D configurations of pivoting modular cube robots with holes of arbitrary shape and number. Cube modules move across the surface of configurations by pivoting about shared edges, enabling configurations to reshape themselves. Previous work provides a reconfiguration algorithm for admissible 3D configurations containing no non-convex holes; we improve upon this by handling arbitrary admissible 3D configurations. The key insight specifies a point in the deconstruction of layers enclosing non-convex holes at which we can pause and move inner modules out of the hole. We prove this happens early enough to maintain connectivity, but late enough to open enough room in the enclosing layer for modules to escape the hole. Our algorithm gives reconfiguration plans with O(n^2) moves for n modules.


Cellular and Modular Robots, Motion and Path Planning, Computational Geometry

Additional Files

pivoting_cubes_2021.mp4 (6061 kB)
Supplementary video showing an example reconfiguration



Date Posted: 13 July 2021

This document has been peer reviewed.